Pulverized coal concentration online monitoring device and coal mill

Abstract

The utility model discloses a pulverized coal concentration online monitoring device and a coal mill. The pulverized coal concentration online monitoring device comprises a gas-solid separation mechanism, a sampling pipe, an exhaust pipe, a sampling container, a weighing mechanism and a negative pressure generation mechanism, the gas-solid separation mechanism is communicated with a pulverized coal pipe through the sampling pipe and the exhaust pipe, the gas-solid separation mechanism is further communicated with the sampling container, the sampling container is placed on the weighing mechanism, and the negative pressure generation mechanism is arranged on the sampling container. The gas-solid separation mechanism, the sampling pipe, the exhaust pipe and the pulverized coal pipe form a loop for airflow circulation, and the negative pressure generation mechanism is communicated with the exhaust pipe and is used for forming a negative pressure environment in the exhaust pipe, so that an air pressure difference for driving airflow to enter the gas-solid separation mechanism along the sampling pipe is formed between the gas-solid separation mechanism and the pulverized coal pipe. The constant-speed sampling of the sampling pipe is realized by designing a mode of monitoring the pressure difference of the sampling pipe and regulating and controlling the vacuum degree of the sampling system, the approximate consistency of the pressure of the sampling port and the internal pressure of the pipeline can be ensured, and the constant-speed sampling device has the advantages of high sensitivity, quick response and short sampling period.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of pulverized coal concentration on-line monitoring device and coal mill, belong to coal-fired power plant coal powder uniform flow technical field. BACKGROUND

[0002] Coal mill is usually equipped with several pulverized coal pipes connected with coal-fired boiler, and the coal conveying capacity of coal distribution pipe is directly related to the combustion efficiency and safety of coal-fired boiler. Under actual operating conditions, the coal conveying capacity of different pulverized coal pipes is often greatly deviated due to the influence of harsh operating conditions of coal mill, which brings safety hazards to boiler operation.

[0003] The detection of coal conveying capacity in the pulverized coal pipe is the key prerequisite for realizing the leveling of the pulverized coal pipe. The current monitoring technology is mostly manual sampling, which faces serious human factor interference and long test cycle, and increases the difficulty of leveling the pulverized coal pipe. SUMMARY

[0004] The main purpose of the utility model is to provide a kind of pulverized coal concentration on-line monitoring device and coal mill, based on the premise of constant speed sampling, which can monitor the coal conveying capacity online, provide reference for further real-time adjustment, so as to overcome the shortcomings of the prior art.

[0005] To achieve the above-mentioned utility model purposes, the technical scheme adopted by the utility model comprises:

[0006] The first aspect of the embodiment of the utility model provides a kind of pulverized coal concentration on-line monitoring device, which is matched with pulverized coal pipe and used for monitoring the pulverized coal concentration in the pulverized coal pipe. The pulverized coal concentration on-line monitoring device comprises:

[0007] Gas-solid separation mechanism, sampling pipe, exhaust pipe, sampling container and weighing mechanism. The gas-solid separation mechanism is communicated with the pulverized coal pipe through the sampling pipe and the exhaust pipe respectively. The gas-solid separation mechanism is also communicated with the sampling container. The sampling container is placed on the weighing mechanism. The gas-solid separation mechanism, the sampling pipe, the exhaust pipe and the pulverized coal pipe form a loop for gas flow circulation.

[0008] The sampling pipe is used to guide the gas flow containing pulverized coal in the pulverized coal pipe into the gas-solid separation mechanism. The gas-solid separation mechanism is used to separate the gas flow containing pulverized coal to form pulverized coal and gas phase medium. The exhaust pipe is used to guide the gas phase medium separated from the gas-solid separation mechanism back to the pulverized coal pipe. The sampling container is used to contain the pulverized coal separated from the gas-solid separation mechanism. The weighing mechanism is used to measure the weight of the pulverized coal in the sampling container.

[0009] And a negative pressure generating mechanism, which is communicated with the exhaust pipe and is used to form a negative pressure environment in the exhaust pipe to form a pressure difference of air flow between the gas-solid separation mechanism and the pulverized coal pipe to drive the air flow into the gas-solid separation mechanism along the sampling pipe.

[0010] The second aspect of the embodiment of the utility model provides a coal mill, the coal mill includes the pulverized coal concentration on - line monitoring device, the pulverized coal concentration on - line monitoring device with the pulverized coal pipe of the coal mill is connected, and be used for monitoring the pulverized coal concentration in the pulverized coal pipe.

[0011] Compared with the prior art, the utility model has the advantages of:

[0012] The coal concentration on - line monitoring device provided by the embodiment of the utility model realizes the constant speed sampling of the sampling pipe through the design of the sampling pipe pressure difference monitoring and the regulation and control of the vacuum degree of the sampling system, can ensure that the sampling port and the internal pressure of the pipeline are approximately consistent, and has the advantages of high sensitivity, rapid response and short sampling period.

[0013] The coal concentration on - line monitoring device provided by the embodiment of the utility model adopts the multi-stage cyclone separator to separate the pulverized coal, can effectively separate the coarse particles and fine particles of the pulverized coal, improves the separation efficiency, and simultaneously monitors the pulverized coal amount conveyed in the pulverized coal pipe in unit time through the weighing method, guarantees the accuracy of the monitoring result.

[0014] The coal concentration on - line monitoring device provided by the embodiment of the utility model realizes the automatic control of the whole test process, test result analysis and information transmission through the central control machine, does not need the intervention of the on - site test process personnel, and reduces the influence of the thinking factor on the test result. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical scheme in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiment or the prior art description will be briefly introduced as follows, and obviously, the drawings in the following description are only some embodiments described in the present application, and those skilled in the art can also obtain other drawings according to these drawings without creating any creative labor.

[0016] Figure 1 It is a structure schematic view of the coal concentration on - line monitoring device provided in a typical embodiment case of the utility model. DETAILED DESCRIPTION

[0017] In view of the deficiencies in the prior art, the present inventors have long-term research and a large number of practices, and have proposed the technical scheme of the utility model. The technical scheme, its implementation process and principles will be further explained as follows.

[0018] The first aspect of the utility model discloses a kind of coal dust concentration online monitoring device, cooperate with coal dust pipe, and for monitoring the coal dust concentration in the coal dust pipe, the coal dust concentration online monitoring device includes:

[0019] Gas-solid separation mechanism, sampling tube, exhaust pipe, sampling container, weighing mechanism, the gas-solid separation mechanism is communicated with the sampling tube, the exhaust pipe and the coal dust pipe respectively, the gas-solid separation mechanism is also communicated with the sampling container, the sampling container is placed on the weighing mechanism, the gas-solid separation mechanism, the sampling tube, the exhaust pipe and the coal dust pipe form a loop that can be supplied with airflow circulation;

[0020] The sampling tube is used to guide the airflow containing coal dust in the coal dust pipe into the gas-solid separation mechanism, the gas-solid separation mechanism is used to separate the airflow containing coal dust to form coal dust and gas phase medium, the exhaust pipe is used to guide the gas phase medium separated from the gas-solid separation mechanism back to the coal dust pipe, and the sampling container is used to accommodate the coal dust separated from the gas-solid separation mechanism.

[0021] And a negative pressure generating mechanism, the negative pressure generating mechanism is communicated with the exhaust pipe, and is used to form a negative pressure environment in the exhaust pipe, to form a gas pressure difference between the gas-solid separation mechanism and the coal dust pipe, which drives airflow into the gas-solid separation mechanism along the sampling tube.

[0022] Further, the gas inlet of the gas-solid separation mechanism is communicated with the sampling tube, the gas outlet is communicated with the exhaust pipe, and the coal dust outlet is communicated with the sampling container.

[0023] Further, the exhaust pipe is further provided with a first on-off valve, and the sampling tube is further provided with a second on-off valve.

[0024] Further, the exhaust pipe includes a first pipe segment, a second pipe segment and a third pipe segment communicated in sequence, the first pipe segment is directly communicated with the gas-solid separation mechanism, the first on-off valve is arranged on the second pipe segment, and the third pipe segment is directly communicated with the coal dust pipe.

[0025] Further, the negative pressure generating mechanism is communicated with the first pipe segment and the second pipe segment, the negative pressure generating mechanism is also communicated with a compressed air pipeline, and a third on-off valve is further arranged on the connecting pipeline between the compressed air pipeline and the negative pressure generating mechanism.

[0026] Further, the compressed air pipeline is also communicated with the sampling container, the compressed air provided by the compressed air pipeline is also used for taking the pulverized coal in the sampling container back to the pulverized coal pipeline, and a fourth switch valve is further arranged on the connecting pipeline between the compressed air pipeline and the sampling container.

[0027] Further, the compressed air pipeline is also communicated with the exhaust pipe, and a fifth switch valve is further arranged on the connecting pipeline between the compressed air pipeline and the exhaust pipe.

[0028] Further, the compressed air pipeline is directly communicated with the third pipe section of the exhaust pipe.

[0029] In a more specific embodiment, the pulverized coal concentration online monitoring device further comprises a differential pressure gauge and a central control instrument, the differential pressure gauge is used for monitoring the air pressure difference between the pulverized coal pipeline and the sampling pipeline, the differential pressure gauge is further connected with the central control instrument, the central control instrument is further connected with the third switch valve, and the central control instrument can adjust the working state of the third switch valve.

[0030] Further, the gas-solid separation mechanism comprises one or more cyclone separators, and the plurality of cyclone separators are connected in series and / or in parallel.

[0031] A second aspect of the embodiment of the utility model provides a coal mill, the coal mill includes the pulverized coal concentration online monitoring device, the pulverized coal concentration online monitoring device is communicated with the pulverized coal pipeline of the coal mill, and is used for monitoring the pulverized coal concentration in the pulverized coal pipeline.

[0032] The technical scheme, its implementation process and principles will be further explained and described as follows, the embodiment of the utility model is described in detail below, wherein the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions throughout. The purpose of this part is to summarize some aspects of the embodiments of the utility model and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this part and the abstract of the specification and the utility model name to avoid obscuring the purpose of this part, the abstract of the specification and the utility model name. Such simplifications or omissions cannot be used to limit the scope of the utility model. The embodiments described below by referring to the drawings are exemplary and are only used to explain the utility model, and cannot be explained as the limitation of the utility model. Unless specifically stated, the negative pressure generating mechanism, switch valve, cyclone separator, differential pressure gauge and central control instrument involved in the embodiments of the utility model can be known in the art, which can be obtained by market purchase, and the specific structure, product model and specific working principle / method are not limited.

[0033] The coal powder concentration on-line monitoring device is matched with the coal powder pipe and is used for monitoring the coal powder concentration in the coal powder pipe, so that the boiler combustion efficiency and operation safety are improved.

[0034] In a more specific embodiment, referring to Figure 1 The coal powder concentration on-line monitoring device comprises a first gas-solid separation mechanism 8, a second gas-solid separation mechanism 9, an exhaust pipe 5, a sampling pipe 6, a sampling container 13, a weighing mechanism 14 and a negative pressure generating mechanism, the first gas-solid separation mechanism 8 and the second gas-solid separation mechanism 9 are connected in series, the second gas-solid separation mechanism 9 is communicated with the coal powder pipe through the sampling pipe 6, the first gas-solid separation mechanism 8 is communicated with the coal powder pipe through the exhaust pipe 5, the first gas-solid separation mechanism 8 and the second gas-solid separation mechanism 9 are also communicated with the sampling container 13, the sampling container 13 is placed on the weighing mechanism 14, the first gas-solid separation mechanism 8, the second gas-solid separation mechanism 9, the sampling pipe 6, the exhaust pipe 5 and the coal powder pipe form a loop through which gas flow circulates, the negative pressure generating mechanism is communicated with the exhaust pipe 5 and is used for forming a negative pressure environment in the exhaust pipe 5, so as to form a gas pressure difference between the first gas-solid separation mechanism 8, the second gas-solid separation mechanism 9 and the coal powder pipe, which drives gas flow to enter the first gas-solid separation mechanism 8 and the second gas-solid separation mechanism 9 along the sampling pipe 6. It should be noted that the power of the gas flow circulating in the loop formed by the first gas-solid separation mechanism 8, the second gas-solid separation mechanism 9, the sampling pipe 6, the exhaust pipe 5 and the coal powder pipe is provided by the negative pressure generating mechanism.

[0035] Specifically, the gas flow containing coal powder in the coal powder pipe enters the second gas-solid separation mechanism 9 and the first gas-solid separation mechanism 8 in sequence through the sampling pipe 6, the second gas-solid separation mechanism 9 and the first gas-solid separation mechanism 8 separate the gas flow containing coal powder to form coal powder and gas phase medium, the gas phase medium obtained by separation through the second gas-solid separation mechanism 9 and the first gas-solid separation mechanism 8 is transported back to the coal powder pipe through the exhaust pipe 5, the separated coal powder is transported to the sampling container 13, the weighing mechanism 14 weighs the sampling container 13 (together with the coal powder in the sampling container 13) in real time, so as to obtain the weight of the coal powder in the sampling container 13.

[0036] Specifically, the first gas-solid separation mechanism 8 and the second gas-solid separation mechanism 9 are cyclones with the same structure, and the cyclones have a gas inlet, a gas outlet and a solid phase outlet. The gas inlet of the second gas-solid separation mechanism 9 is directly communicated with the sampling pipe 6, and the gas outlet is communicated with the gas inlet of the first gas-solid separation mechanism 8. The gas inlet of the first gas-solid separation mechanism 8 is communicated with the exhaust pipe 5, and the solid phase outlets of the first gas-solid separation mechanism 8 and the second gas-solid separation mechanism 9 are respectively communicated with the sampling container 13. It should be noted that the equipment models of the first gas-solid separation mechanism 8 and the second gas-solid separation mechanism 9 can be the same or different, and preferably cyclones with the same structure and the same model are selected. In addition, the case of two serially connected gas-solid separation mechanisms is shown in the figure, but the pulverized coal concentration online monitoring device can of course include a larger number of gas-solid separation mechanisms. The plurality of gas-solid separation mechanisms can be connected in series, or can be connected in series and parallel combination to improve the separation efficiency and effect of the pulverized coal, and thus improve the accuracy of the pulverized coal concentration detection result.

[0037] More specifically, the sampling pipe 6 and the exhaust pipe 5 are both communicated with the pulverized coal pipe, and the communication position of the sampling pipe 6 with the pulverized coal pipe is located upstream of the communication position of the exhaust pipe 5 with the pulverized coal pipe. Here, the upstream position is referenced to the flow direction of the gas flow containing the pulverized coal in the pulverized coal pipe.

[0038] Specifically, the exhaust pipe 5 is further provided with a first switch valve 4, and the sampling pipe 6 is further provided with a second switch valve 7. More specifically, the exhaust pipe 5 includes a first pipe section, a second pipe section and a third pipe section communicated in sequence. The first pipe section is directly communicated with the second gas-solid separation mechanism 8, the first switch valve 4 is arranged on the second pipe section, the third pipe section is directly communicated with the pulverized coal pipe, and the first pipe section and the second pipe section of the negative pressure generating mechanism 3 are directly communicated, respectively. A third switch valve 2 is further arranged on the connecting pipeline between the compressed air pipeline and the negative pressure generating mechanism 3. By adjusting the working states of the first switch valve 4, the second switch valve 7 and the third switch valve 2, the working state of the pulverized coal concentration online monitoring device can be controlled. For example, the negative pressure generating mechanism 3 can be a vacuum generator.

[0039] Specifically, the coal concentration online monitoring device further comprises a differential pressure gauge 10 and a central control instrument 11, the differential pressure gauge 10 is used to monitor the pressure difference between the coal pipe and the sampling pipe 6, the differential pressure gauge 10 is also connected with the central control instrument 11, the central control instrument 11 is also connected with the third switch valve, and the central control instrument 11 can adjust the working state of the third switch valve 2. Specifically, the differential pressure gauge 10 monitors the pressure difference between the sampling pipe 5 and the coal pipe in real time, and transmits signals to the central control instrument 11, which analyzes and determines the working parameters / working state of the third switch valve 2, adjusts the negative pressure in the sampling pipeline, ensures that the pressure difference between the sampling pipe 5 and the coal pipe is maintained within a certain range, and finally realizes the effect of constant-speed sampling.

[0040] More specifically, the compressed air pipeline is also connected with the sampling container 13, the compressed air provided by the compressed air pipeline is also used to carry the coal powder in the sampling container 13 back to the coal pipe, the compressed air pipeline is also connected with the exhaust pipe 5, and the compressed air provided by the compressed air pipeline is also used to blow gas for the whole coal concentration online monitoring device. More specifically, a fourth switch valve 12 is arranged on the connecting pipeline between the compressed air pipeline and the sampling container 13, and a fifth switch valve 1 is arranged on the connecting pipeline between the compressed air pipeline and the exhaust pipe 5, wherein the compressed air pipeline is directly connected with the third pipe section of the exhaust pipe 5.

[0041] It should be noted that the sampling container 13 can be a sampling crucible or the like, and the weighing mechanism 14 can be an electronic scale known in the art.

[0042] Specifically, the negative pressure generating mechanism 3 is connected with the exhaust pipe 5, during sampling, the compressed air provided by the compressed air pipeline drives the negative pressure generating mechanism 3 to work, negative pressure is generated in the exhaust pipe 5 and the sampling pipe 6 connected therewith, the coal powder in the coal pipe enters the sampling pipe 6 along the airflow, and then enters the second gas-solid separation mechanism 9 and the first gas-solid separation mechanism 8 for gas-solid separation, the separated coal powder falls into the sampling container 13, and the gas enters the coal pipe along the exhaust pipe 5 from the gas outlet of the first gas-solid separation mechanism 8, forming a closed loop circulation and realizing the sampling process. After sampling, the sampling quality is analyzed by the weighing mechanism 14 to obtain the coal conveying amount data. After sampling, the sampling container 13 is cleaned, the compressed air provided by the compressed air pipeline enters the sampling container 13 through the fourth switch valve 12, the coal powder in the sampling container 13 enters the exhaust pipe 5 and the sampling pipe 6 along with the airflow, and finally returns to the coal pipe, and the weighing mechanism 14 monitors the quality of the sampling container 13 in real time until it is cleaned and blown dry. More specifically, the exhaust pipe and the sampling pipe can also be cleaned by the compressed air provided by the compressed air pipeline.

[0043] The embodiment of the utility model provides a kind of pulverized coal concentration on-line monitoring device, by design sampling tube pressure difference monitoring, the vacuum degree of regulation and control sampling system realizes the isokinetic sampling of sampling tube, can guarantee that sampling port and pipeline internal pressure are approximately identical, with the advantage of high sensitivity, response is quick, sampling cycle is short.

[0044] The embodiment of the utility model provides a kind of pulverized coal concentration on-line monitoring device, adopts multistage cyclone separator to carry out pulverized coal separation, can effectively separate pulverized coal coarse particle and fine particle, improves separation efficiency, simultaneously by weighing method, the coal powder quantity of coal powder pipe in unit time is monitored, guarantees the accuracy of monitoring result.

[0045] The embodiment of the utility model provides a kind of pulverized coal concentration on-line monitoring device, realizes test whole process automatic control by central control machine, test result analysis and information transmission, without field test process personnel intervention, reduce the influence of considered factor to test result.

[0046] It should be understood that the above embodiments are only for illustrating the technical concept and characteristics of the utility model, and the purpose is to enable persons skilled in the art to understand the content of the utility model and to implement it, and it cannot limit the protection scope of the utility model. Any equivalent change or modification made according to the spirit and essence of the utility model shall be covered within the protection scope of the utility model.

Claims

1. An online coal powder concentration monitoring device, used in conjunction with a coal powder pipe and for monitoring the coal powder concentration within the coal powder pipe, characterized in that, The online coal powder concentration monitoring device includes: The system includes a gas-solid separation mechanism, a sampling pipe, an exhaust pipe, a sampling container, and a weighing mechanism. The gas-solid separation mechanism is connected to the pulverized coal pipe via the sampling pipe and the exhaust pipe, and is also connected to the sampling container. The sampling container is placed on the weighing mechanism. The gas-solid separation mechanism, the sampling pipe, the exhaust pipe, and the pulverized coal pipe form a loop that allows airflow. The sampling tube is used to guide the airflow containing coal powder in the coal powder tube into the gas-solid separation mechanism. The gas-solid separation mechanism is used to separate the airflow containing coal powder into coal powder and gaseous medium. The exhaust pipe is used to guide the gaseous medium obtained by the gas-solid separation mechanism back to the coal powder tube. The sampling container is used to contain the coal powder obtained by the gas-solid separation mechanism. The weighing mechanism is used to measure the weight of the coal powder in the sampling container. And a negative pressure generating mechanism, which is connected to the exhaust pipe and is used to create a negative pressure environment in the exhaust pipe to create a pressure difference between the gas-solid separation mechanism and the pulverized coal pipe that drives the airflow to enter the gas-solid separation mechanism along the sampling pipe.

2. The online coal powder concentration monitoring device according to claim 1, characterized in that: The gas-solid separation mechanism has an air inlet connected to the sampling pipe, an air outlet connected to the exhaust pipe, and a coal powder outlet connected to the sampling container.

3. The online coal powder concentration monitoring device according to claim 1 or 2, characterized in that: The exhaust pipe is also equipped with a first switching valve, and the sampling pipe is also equipped with a second switching valve.

4. The online coal powder concentration monitoring device according to claim 3, characterized in that: The exhaust pipe includes a first pipe section, a second pipe section, and a third pipe section connected in sequence. The first pipe section is directly connected to the gas-solid separation mechanism, the first switch valve is installed on the second pipe section, and the third pipe section is directly connected to the pulverized coal pipe.

5. The online coal powder concentration monitoring device according to claim 4, characterized in that: The negative pressure generating mechanism is connected to the first pipe section and the second pipe section. The negative pressure generating mechanism is also connected to the compressed air pipeline. Furthermore, a third switching valve is provided on the connecting pipeline between the compressed air pipeline and the negative pressure generating mechanism.

6. The online coal powder concentration monitoring device according to claim 5, characterized in that: The compressed air pipeline is also connected to the sampling container. The compressed air provided by the compressed air pipeline is also used to bring the coal powder in the sampling container back to the coal powder pipe. Furthermore, a fourth switching valve is provided on the connecting pipeline between the compressed air pipeline and the sampling container.

7. The online coal powder concentration monitoring device according to claim 5 or 6, characterized in that: The compressed air pipeline is also connected to the exhaust pipe, and a fifth switching valve is provided on the connecting pipeline between the compressed air pipeline and the exhaust pipe. And / or, the compressed air pipeline is directly connected to the third section of the exhaust pipe.

8. The online coal powder concentration monitoring device according to claim 5, characterized in that, Also includes: The differential pressure gauge and the central control unit are used to monitor the gas pressure difference between the pulverized coal pipe and the sampling pipe. The differential pressure gauge is also connected to the central control unit, which is also connected to the third switching valve. The central control unit can adjust the working state of the third switching valve.

9. The online coal powder concentration monitoring device according to claim 1, characterized in that: The gas-solid separation mechanism includes one or more cyclone separators, and the plurality of cyclone separators are connected in series and / or in parallel.

10. A coal mill, characterized in that, The coal mill includes the online coal powder concentration monitoring device according to any one of claims 1-9, wherein the online coal powder concentration monitoring device is connected to the coal powder pipe of the coal mill and is used to monitor the coal powder concentration in the coal powder pipe.

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